Malicious PDF — malware analysis report

Static analysis result for SHA-256 799898998a5035d7…

MALICIOUS

PDF

89.3 KB Created: 2021-09-18 01:23:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 110ae2e5101753c745f3fd0cd231c3c3 SHA-1: 772f73f63efb33844750b6ce48b73c865bdd57e8 SHA-256: 799898998a5035d74344b1914c35bfc8f1b6d57ec7718bb2506fe88aa5084b61
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The heuristics reveal the PDF acts as a link farm, containing numerous embedded URLs pointing to other PDF files hosted on various domains. One URL, 'http://dogalakustik.com/depo/sayfaresim/file/xofuvukugakokurufikexobi.pdf', is identified as part of this link farm. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather for programmatic interaction.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://dogalakustik.com/depo/sayfaresim/file/xofuvukugakokurufikexobi.pdf In PDF document text
    • https://joebalogh.ro/imagini_ws/40628772818.pdfIn PDF document text
    • http://1night2daytour.com/ckupload/files/natog.pdfIn PDF document text
    • https://mami-m.com/Uploads/userfiles/files/91505232103.pdfIn PDF document text
    • http://ch-bovi.com/upload/files/31983287575.pdfIn PDF document text
    • http://kaitosushisb.com/uploads/files/84700198642.pdfIn PDF document text
    • http://acudrved.com/ckfinder/userfiles/files/47334552486.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/1asceo1j60ckp3cf1fvd2t1k1o/44728155082.pdfIn PDF document text
    • https://www.rapn.ru/ckfinder/userfiles/files/xidekurajavubebo.pdfIn PDF document text
    • http://cesurmakina.com/userfiles/file/396571072.pdfIn PDF document text
    • http://moristas.com/userfiles/files/92979032816.pdfIn PDF document text
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/43132219276.pdfIn PDF document text
    • http://www.pes.edu.mn/ckfinder/userfiles/files/60063868765.pdfIn PDF document text
    • http://ambcavallon.eu/userfiles/files/49298946483.pdfIn PDF document text
    • https://lordoptika.hu/files/files/8054292884.pdfIn PDF document text
    • http://studionegro.net/userfiles/files/53215728255.pdfIn PDF document text
    • https://robodom.si/files_vsebine/vusegifexerijogokovi.pdfIn PDF document text
    • https://ego-sofa.tw/uploads/files/202109090534225062.pdfIn PDF document text
    • http://larben.cz/media/images/upload/file/75296121595.pdfIn PDF document text
    • http://vlaamspatientenplatform.be/_plugin/ckfinder/userfiles/files/pagorujijo.pdfIn PDF document text
    • https://vsevolozhsk.mebel18.com/uploads/files/53053809605.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/rekekisoje.pdfIn PDF document text
    • http://cukierniabrzezinski.pl/www/artizam/fck/file/suvajomubules.pdfIn PDF document text
    • http://yesilderecine.com/admin/editor_resim/file/39255013192.pdfIn PDF document text
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210906000035.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=playstation+gift+card+generator+2021PDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f62a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF62A 18224 bytes
SHA-256: dccf00fbf3f826178e6dc323ce2344965406229496a752e042252b5a1cbf470e
font_01_sfnt_off0001254d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1254D 11060 bytes
SHA-256: 33ddab1c58feff08314ec50293a224a51a203c9d93ad172f67698427f17b7031
font_02_sfnt_off00013f29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F29 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1